Surging

[markusedma]

I have an '03 Jetta 1.8t 5spd with the upsolute programming done. It was done at the dealer when I bought the car new. I have a problem with the car surging under acceleration you can feel it the most in 3rd gear with 3/4 to full throttle around 4000rpms, you can hear the turbo spooling up and then down then up and down when it does this. The problem started last spring. The car only has 15000kms on it. I took it to the dealer and they had the car for 3 months and could not fix it, they replaced the BOV with a aftermarket unit, changed the MAF sensor and drove the car. One of the techs from ubsolute finally came down to the dealer and looked but could not come to a conclusion. They said the car was better after what they had done and to try it out. Well it still does it. Now they say that maybe I need an aftermarket fuel press. regulator... And suggestions?

 

[avihai]

It looks like a lean mixture problem we have the same problem with some cars when we change the down pipe to a 3”
We have a lot of experience with the 1.8t tuning and ali from upsolute help us to find the best chips for the 1.8t engine with different tuning if you can send your ecu NO I can tell you which file will be the best for your set up
If you drive more then 100000km It will be good thing to check your fuel pump when you drive the car the fuel pressure should be with 3 bar fpr 3 bar plus the boost you boosting if you boost 1 bar it should be 4 bar
If its ok you can use a vag com to measure the lambda temperature on channel 34 if it goes more then 950 c you are running lean and the ecu take the boost down to protect the engine

 

[René]

Contact me by email and I will Have Upsolute Toronto contact you directly, we probably have a revised file for you, if the revision does not clear up the surging completely the N75 valve might need to be changed on this model.